Change the max_swipe_deviation_ratio to max_swipe_deviation_angle.

Angle makes more sense here to determine if it is a swipe gesture.

R=tdresser@chromium.org
BUG=366603

Review URL: https://codereview.chromium.org/452153004

Cr-Commit-Position: refs/heads/master@{#288785}
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@288785 0039d316-1c4b-4281-b951-d872f2087c98

5 files changed, 29 insertions, 13 deletions

diff --git a/ui/aura/gestures/gesture_recognizer_unittest.cc b/ui/aura/gestures/gesture_recognizer_unittest.cc
index b57e4cd..963b24d 100644
--- a/ui/aura/gestures/gesture_recognizer_unittest.cc
+++ b/ui/aura/gestures/gesture_recognizer_unittest.cc
@@ -2890,6 +2890,21 @@ TEST_P(GestureRecognizerTest, MultiFingerSwipe) {
         count, points, 10, kSteps, 11 * kSteps, 0);
     EXPECT_TRUE(delegate->swipe_right());
     delegate->Reset();
+
+    generator.GestureMultiFingerScroll(
+        count, points, 10, kSteps, 5 * kSteps, 12 * kSteps);
+    EXPECT_FALSE(delegate->swipe_down());
+    delegate->Reset();
+
+    generator.GestureMultiFingerScroll(
+        count, points, 10, kSteps, 4 * kSteps, 12 * kSteps);
+    EXPECT_TRUE(delegate->swipe_down());
+    delegate->Reset();
+
+    generator.GestureMultiFingerScroll(
+        count, points, 10, kSteps, 3 * kSteps, 12 * kSteps);
+    EXPECT_TRUE(delegate->swipe_down());
+    delegate->Reset();
   }
 }
 
diff --git a/ui/events/gesture_detection/gesture_config_helper_aura.cc b/ui/events/gesture_detection/gesture_config_helper_aura.cc
index c6c18f7..195e891 100644
--- a/ui/events/gesture_detection/gesture_config_helper_aura.cc
+++ b/ui/events/gesture_detection/gesture_config_helper_aura.cc
@@ -2,9 +2,6 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// MSVC++ requires this to be set before any other includes to get M_PI.
-#define _USE_MATH_DEFINES
-
 #include "ui/events/gesture_detection/gesture_config_helper.h"
 
 #include <cmath>
@@ -36,8 +33,7 @@ GestureDetector::Config DefaultGestureDetectorConfig() {
   config.swipe_enabled = true;
   config.minimum_swipe_velocity = GestureConfiguration::min_swipe_speed();
   config.maximum_swipe_deviation_angle =
-      atan2(1.f, GestureConfiguration::max_swipe_deviation_ratio()) * 180.0f /
-      static_cast<float>(M_PI);
+      GestureConfiguration::max_swipe_deviation_angle();
   config.two_finger_tap_enabled = true;
   config.two_finger_tap_max_separation =
       GestureConfiguration::max_distance_for_two_finger_tap_in_pixels();
diff --git a/ui/events/gestures/gesture_configuration.cc b/ui/events/gestures/gesture_configuration.cc
index 8623e99..5b22639 100644
--- a/ui/events/gestures/gesture_configuration.cc
+++ b/ui/events/gestures/gesture_configuration.cc
@@ -18,7 +18,7 @@ int GestureConfiguration::max_radius_ = 100;
 double GestureConfiguration::max_seconds_between_double_click_ = 0.7;
 double
   GestureConfiguration::max_separation_for_gesture_touches_in_pixels_ = 150;
-double GestureConfiguration::max_swipe_deviation_ratio_ = 3;
+float GestureConfiguration::max_swipe_deviation_angle_ = 20;
 double
   GestureConfiguration::max_touch_down_duration_in_seconds_for_click_ = 0.8;
 double GestureConfiguration::max_touch_move_in_pixels_for_click_ = 15;
diff --git a/ui/events/gestures/gesture_configuration.h b/ui/events/gestures/gesture_configuration.h
index 1e3ea68..81f3ae0 100644
--- a/ui/events/gestures/gesture_configuration.h
+++ b/ui/events/gestures/gesture_configuration.h
@@ -71,11 +71,11 @@ class EVENTS_BASE_EXPORT GestureConfiguration {
   static void set_max_separation_for_gesture_touches_in_pixels(int val) {
     max_separation_for_gesture_touches_in_pixels_ = val;
   }
-  static double max_swipe_deviation_ratio() {
-    return max_swipe_deviation_ratio_;
+  static float max_swipe_deviation_angle() {
+    return max_swipe_deviation_angle_;
   }
-  static void set_max_swipe_deviation_ratio(double val) {
-    max_swipe_deviation_ratio_ = val;
+  static void set_max_swipe_deviation_angle(float val) {
+    max_swipe_deviation_angle_ = val;
   }
   static double max_touch_down_duration_in_seconds_for_click() {
     return max_touch_down_duration_in_seconds_for_click_;
@@ -238,7 +238,7 @@ class EVENTS_BASE_EXPORT GestureConfiguration {
   static double semi_long_press_time_in_seconds_;
   static double max_seconds_between_double_click_;
   static double max_separation_for_gesture_touches_in_pixels_;
-  static double max_swipe_deviation_ratio_;
+  static float max_swipe_deviation_angle_;
   static double max_touch_down_duration_in_seconds_for_click_;
   static double max_touch_move_in_pixels_for_click_;
   static double max_distance_between_taps_for_double_tap_;
diff --git a/ui/events/gestures/gesture_sequence.cc b/ui/events/gestures/gesture_sequence.cc
index e20e702..838a6a1 100644
--- a/ui/events/gestures/gesture_sequence.cc
+++ b/ui/events/gestures/gesture_sequence.cc
@@ -2,6 +2,9 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+// MSVC++ requires this to be set before any other includes to get M_PI.
+#define _USE_MATH_DEFINES
+
 #include "ui/events/gestures/gesture_sequence.h"
 
 #include <stdlib.h>
@@ -1412,9 +1415,11 @@ bool GestureSequence::MaybeSwipe(const TouchEvent& event,
   if (!swipe_y)
     velocity_y = 0.001f;
 
-  float ratio = velocity_x > velocity_y ? velocity_x / velocity_y :
+  float ratio = velocity_x < velocity_y ? velocity_x / velocity_y :
                                           velocity_y / velocity_x;
-  if (ratio < GestureConfiguration::max_swipe_deviation_ratio())
+  float angle = atan(ratio) * 180.0f / static_cast<float>(M_PI);
+
+  if (angle > GestureConfiguration::max_swipe_deviation_angle())
     return false;
 
   if (velocity_x > velocity_y)